<!DOCTYPE html>
<!-- Any copyright is dedicated to the Public Domain.
   - http://creativecommons.org/publicdomain/zero/1.0/ -->

<html>
  <style>
  /* This is not a user agent style sheet, so the style will be ignored.
     "testing.supports.moz-bool-pref" is set to true in
     layout/tools/reftest/reftest-preferences.js. */
  @supports -moz-bool-pref("testing.supports.moz-bool-pref") {
    p {
      background-color: red;
    }
  }
  </style>
  <body>
    <p>This text should not have background color.</p>
  </body>
</html>